With the ever increasing need for providing higher and increased speeds of electronic assembly circuitry, there is increasing interest in using the surface mount terminals since this eliminates the need for holes through the circuit board and the space considerations associated therewith. It is further desirable that the surface mount terminals have mechanically compliant sections, such as a spring section, to assure a sufficient normal force between the mating terminal and circuit pad. It is further desirable to provide terminal members that can be assembled in a dense array. In high speed interconnections, however, it is also desirable to provide as short as possible electrical path through the terminal members.
One type of spring arm terminal known in the art has an "open spring", which provides the increased compliancy but greatly increases the length of the electrical path.
U.S. Pat. No. 4,898,539 shows one example of a surface mount pin terminal having a compliant pin section having one end thereof attached to a body portion of the terminal and extending to a contact surface proximate the second end of the spring and further including a stub portion at the end of the spring. When the terminal is in its mated position the stub is forced against a body portion of the spring thereby providing a circular path or "closed loop". Other "closed loop" designs are shown in U.S. Pat. No. 4,895,521, which discloses a C-shaped type pin extending from a body portion of the terminal to provide resiliency, the end of the C-shape again being engaged to form a "closed loop" with the terminal body and in U.S. Pat. No. 4,998,887, which discloses terminal in which the free end of the spring is brought into engagement with the body of the terminal when the connector is mounted to the circuit board. While "closed loop" designs provide more than one current path, the problems associated with maintaining manufacturing tolerances within the required range are increased.
It is desirable, therefore, to have a spring arm terminal that has the increased compliancy of the spring without increasing the length of the current path nor affecting the range of manufacturing and assembly tolerances.